Re: MORE lsx wiring questions
 

Internal or external pump?
I have seen this before....ther is a positive and negative on the pump. I have seen people wire them backwards and it will buzz like it should but it wont pump.
Something to check

Re: MORE lsx wiring questions
 

Internal..I will check that out..thanks

Re: MORE lsx wiring questions
 

If possible, disconnect everything on that box. Grab (1) relay and wire it for the fuel pump relay. In this order, Id test the fuel pump signal first. If that works, connect and wire the fuel relay by itself.
30-Fused Battery Power
87-Power to (+) on Fuel Pump
Note: Fuel Pump must have Ground(-) also
85-Fuel Pump Signal
Note: PCM Sends (+) Fuel Pump Signal
86-Ground(-)
Note: #85 & #86 can change polarity, which means that the signals are interchangeable, but you must have both the (-) & (+) to power the relay/accessory properly.
These are relays instructions I die by. If someone wires a relay in this fashion and it doesn't work, I'll shoot myself in the foot.

Re: MORE lsx wiring questions
 

Will do! Thanks, i will report back..

Re: MORE lsx wiring questions
 

So i pulled the fuel pump wires off the (Current performance/wired to there isnstructions) relay and wired it up like you suggested to a separate relay....BINGO...fuel pumps seems to come on properly....truck still wont fire so i guess i need to search for the next issue...

Re: MORE lsx wiring questions
 

Double check to make sure your coils and injectors are getting power. Also make sure the crank and cam sensors are plugged in.

How long has the engine been sitting? Could have stuck injectors.

Re: MORE lsx wiring questions
 

Make sure the injectors and fuel pump are receiving a constant 12V while you are engaging the starter.

Re: MORE lsx wiring questions
 

No clue how long the motor has been sitting...Was almost thinking of just buying new injectors because of that fact..Will check power next.

I will check that..Thanks

Re: MORE lsx wiring questions
 

smartass12, no need to buy new fuel injectors, there is a product called Sea Foam. Submerge the fuel injectors for 24 hours and reinstall them. that's how I cleaned my injectors.

Re: MORE lsx wiring questions
 

this stuff is sold at the auto parts store. Also is your PCM sending a fuel pump Signal?

Re: MORE lsx wiring questions
 

ill try that first then.. Also is it safe to assume the PCM is sending signal if the pump kicks on for the two seconds when the key is switched on or is it better to check for signal as engine is being cranked over?

Re: MORE lsx wiring questions
 

when you turn the key, and the fuel pump turns on for two seconds, then turns off your, then you are on the road to LSX freedom. Also, when you turn on the key power, (+12v Switch), things such as coil packs, MAF sensor, injectors, O2 sensors, Tranny, and Tac Module/foot pedal should have power. the above listed items are waiting for the PCM to send ground to operate them in proper PCM Fashion.

Re: MORE lsx wiring questions
 

The fuel pump NOW does just that. So in terms of the others having power does that mean i can check for power at there respected connectors with the key on?

Re: MORE lsx wiring questions
 

Yes. ;)

Re: MORE lsx wiring questions
 

If you are still planning on doing or re-doing the battery in back, you can take a look at what we did on my 66 in our video.

Re: MORE lsx wiring questions
 

thanks for the info. i did already move it to the rear.

Re: MORE lsx wiring questions
 

lol, welding cat